SYNTAX: Notion in checking theory. Informally, the checking domain of a head A consists of everything adjoined to it, and of its specifier(s). Formally, the checking domain of a head A is defined as the minimal residue of A. The residue of A is its domain minus its complement domain.
EXAMPLE: In the following structure (with a head H adjoined to X), the checking domain of X consists of UP, ZP, WP and H. The checking domain of H is UP, ZP and WP.